With the development of information communication technology, there is an increasing demand for various multimedia services in a short-range wireless environment. Wireless Local Area Network (WLAN) is the representative of wireless communication technologies for satisfying such demand. The WLAN enables users to access the Internet wirelessly with their respective mobile devices such as smart phones, smart pads, tablets, laptop computers, etc. in any place where users go. Such a WLAN is evaluated as the most economical and high communication infrastructure in the era of increasing data traffic.
Mobile devices are operated by a battery. As use of data traffic via the mobile device increases, power consumption of the battery rapidly increases. Accordingly, many methods for reducing power consumption in mobile devices are being actively discussed.